1Prince MJ,Harwood RH,Blizard RA,et al.Impairment,disability and handicap as risk hctors for depression in old age[J].Cambridge University Press,1997,27(2):311-321.
2Copeland JR,Beekman AT,Dewey ME,et al.Depression in EuropeGeographical distribution among older people[J].The British Journal of Psychiatry,1999,174:312-321.